Water responsive control circuit



July 10, 1956 R. B. GOLDMAN 2,754,460

WATER RESPONSIVE CONTROL CIRCUIT Filed May 25, 1954 Kg ;,4; 1 .LE

FT X JE "M I E E INVENTOR.

1905527- B. GOLD/WW L ilnited States Patent lt-ice 2,754,460 PatentedJuly 10-, 1955 WATER RESPONSIVE CONTROL CIRCUIT Robert B. Goldman,Forest Hills, N. Y.

Application May 25, 1954, Serial No. 432,108

7 Claims. (Cl. 318-102) My invention relates to a water responsivecontrol circuit and more particularly to a control circuit for use inautomotive vehicles of the convertible type for first raising thewindows and then erecting the top in event of rain.

There are a number of water operated circuits known to the art forcontrolling the erection of the tops of convertible automobiles. Theoperation of such devices is initiated by a water sensitive relay andthe cycle is completed by a limit switch. If it were attempted to applythis principle to the raising of the windows of a convertible, aplurality of limit switches would be required to act when the windowswere in raised position. The installation of such limit switches isawkward and expensive. There is another difficulty which is moreserious, however. In an automotive vehicle, the power for the operationof the motors must come from the storage battery of the car. Theoperation of four window motors simultaneously when the generator is notrunning would draw a higher current than the battery is designed todeliver. I have found, accordingly, that it is necessary to operate thewindow motors in succession.

One object of my invention is to provide a water re sponsive controlcircuit in which the windows of an automotive vehicle will be raised insuccession followed by the erection of the top in response to water fromraindrops acting upon a water sensitive switch.

Another object or my invention is to provide a water sensitive controlcircuit in which the operation of a motor is initiated by a watersensitive switch and in which the motor is de-energized in response toan increased load of predetermined proportions.

Another object of my invention is to provide a water responsive controlcircuit in which the operation of a plurality of motors in succession isinitiated by a water sensitive switch and the successive operation ofthe motors is controlled by successive increases in load upon themotors.

Other and further objects of my invention will appear from the followingdescription.

In general my invention contemplates the provision of a plurality ofmotors, one for raising each of the windows and one for erecting thetop. A first relay is adapted to be energized in response to a watersensitive switch. The energization of the first relay initiates theoperation of the first motor and raises one of the windows. The motorcircuit is completed by a normally closed switch adapted to be opened bya series connected relay winding. An increase in current owing to anincreased load upon the motor, created by the window reaching its limitof travel or otherwise, energizes the relay sufliciently to open thenormally closed switch. The opening of the normally closed switchinterrupts the motor circuit but permits current to flow through aparallel high resistance relay winding, first, to hold the first motorcircuit in open position and simultaneously to hold a normally openswitch of a successive motor in closed position. In this manner each ofthe motors are successively energized and de-energized at the limit oftravel of the member operated by the motor until the final motor isoperated. The final motor usually erects the top and this motor istie-energized by a mechanically opened, normally closed limit switch.The entire arrangement is adapted to be rendered inoperative by closingthe ignition switch of the automotive vehicle. In this manner the normaloperating controls for the windows and top may be employed while theoperator is in the car. The instant control circuit is intended tooperate only in the absence of the owner. It is to be under stood, ofcourse, that while I have described my invention with respect to thecontrol of a plurality of motors for the operation of automotive vehiclewindows and top that my invention may be employed to control any otherappropriate device. For example, my arrangement can be employed to closethe windows of a house in the absence of an owner. I consider a salientfeature of my invention the arrangement whereby the action of the motor,having been initiated, is automatically stopped by an increase in loadin a manner to hold the motor circuit in an inoperative condition and atthe same time maintain another switch in a closed position.

In the accompanying drawings which form part of the instantspecification and which are to be read in conjunction therewith and inwhich like reference numerals are used to indicate like parts in thevarious views:

Figure l is a diagrammatic view of a control circuit containing oneembodiment of my invention.

Figure 2 is a perspective view showing one form of water sensitiveswitch which may be used in carrying out my invention.

More particularly referring now to the drawings, the conductor it) isconnected to a positive terminal 12 of a potential source, such abattery. The conductor 14 is adapted to be connected to the terminal 16which is the ground or index terminal of the battery. I will describe myinvention with respect to an automotive vehicle in which the potentialsource is a storage battery. It is to be understood, of course, that anysuitable potential source may be employed when my control circuit isemployed for other uses. Inasmuch as I desire to render my controlcircuit inoperative when the car is being driven, I arrange my watersensitive switch W across the potential source in series with a normallyclosed manual switch 18, a mechanically operated limit switch LS, anormally closed relay operated switch 1R1 and a relay winding R2. Itwill be observed that the relay winding R2 will be energized wheneverthe circuit is closed across water sensitive switch W, provided themanual switch 18, the limit switch LS and the relay switch 1R1 are intheir closed positions. The water sensitive switch W is shown in Figure2. It comprises an insulating base 22 upon which is mounted a pair ofgrids 24 and 25 formed of respective interdigitating fingers 26 and 23.Binding post 30 connects with grid 24 and its fingers 26 while bindingpost 32 connects with grid 25 and its fingers 28. The space between thepair of adjacent fingers 26 and 23 is quite small and suflicient to bebridged by a single small drop of water. The grid may be formed in anyappropriate manner, as for example, by electrodepositing a conductivemetal upon the insulating back 22. The metal is then covered with a waxor other protective coating. The grids may be formed by scribing theoutlines of the interdigitating fingers through the protective coatingand then etching through the conductive metal by means of acid. Anyappropriate means for mounting the grid (not shown) in an exposedposition upon the car may be provided. Distilled water is not aconductor. The first drops of rainfall, however, dissolve sufficientimpurities in the atmosphere so that the initial drops of rain form anelectrolytic solution adapted readily to conduct current. Furthermore,the grid itself will be coated with deposited salts and other solublematter. The relay R2, controlled by the water sensitive switch W, is asensitive one owing to the fact that the current density through a dropof water must necessarily be low.

In order to render the control circuit inoperative when the ignition isenergized, an ignition key operated switch K is adapted to energizerelay winding R1. The energization of winding R1 opens its normallyclosed relay operated switch 1R1 to interrupt the circuit which would'be completed through relay winding R2 by water sensitive switch W. Itwill also be observed that the operation of my control can be stopped atany point by interrupting the circuit through relay winding R2 by meansof a normally closed manual switch 13. The circuit through relay windingR2 can also be interrupted by opening a normally closed limit switch LS.This switch may be of any appropriate design and is adapted to be openedby movement of the top to its erected position.

Relay winding R2 controls a normally open switch 1R2. Whenever windingR2 is energized, switch 1R2 closes thus energizing relay winding R3.Relay winding R3 controls two switches, namely 1R3 and 2R3. Switch 1R3is adapted to hold the relay winding R3 in energized condition after thecircuit through relay winding R2 is broken, as would be the case if adrop of water evaporated or ran from the water sensitive switch W. Motor40 controls the first window and is adapted to be connected across theline by normally open relay switch 2R3. This switch is connected inseries with a normally closed switch 1R4 and a low impedance relaywinding R4L. The winding 41 is the shunt field winding for the motor 40.The core of relay winding R4L has wound around it a high impedance relaywinding R il-i. The winding Ri-I is connected in parallel with thecircuit segment formed by the low impedance winding R4L and the normallyclosed relay switch 1R4, as can readily be seen by reference toFigure 1. Upon the closing or" switch 2R3 the transient reactanceprevents the current passing through winding R4L from reaching a pointhigh enough to actuate the armature of the relay. This armature, whenactuated, opens the normally closed switch 1R4 and simultaneously closesthe normally open switch 2R4. Upon the closing of theswitch 2R3, thecurrent will begin to build up through winding R tL causing the armatureof motor 40 to rottae. The counter electromotive force generated by thearmature of the motor 40 continues to prevent the current throughwinding RdL from reaching a level high enough to actuate the relayarmature after the transient reactance has subsided and the current hasreached a steady state. actance, which is equivalent of electricalinertia, the physical inertia of the armature assists in preventing theimmediate opening of the switch 1R4 when the current transiently exceedsits normal actuating level. With the steady state achieved, the motorcontinues to run raising the number one window of the automotivevehicle. When the window reaches the limit of its travel, there is anincreased load upon the motor slowing down its armature and reducing thecounter e. m. f. The reduction in the counter e. m. f. raises thecurrent flowing through relay winding R4L sufliciently over its steadystate level to move the relay armature to open switch 1R4 and closeswitch 2R4. While switch 1R4 was closed, the resistance through windingR4L was so low that very little current flowed through winding R4H. Whenswitch 1R4 opens, however, increased current will flow through highimpedance winding R4H. The high resistance of the winding is such thatthere is insuflicient current to operate the motor 49 or to produce anysubstantial current drain upon the battery. The current, however, issufficient to maintain the armature of the relay R4 in its actuatedposition, that is, with switch 1R4- open and switch 2R4 closed.

The closing of switch 2R4 energizes the motor 5v), which is providedwith a field winding 51, through the normally closed relay switch 1R5and the low impedance In addition to the transient rcrelay winding RSL.The high resistance relay winding RSI-I is connected across the normallyclosed switch 1R5 and the winding RSL. The relay R5, of which windingsR5L and RSH form part, controls normally closed relay switch 1R5 andnormally open relay switch 2R5. The motor may drive the mechanism forraising the second window. When this window reaches its limit of travel,the armature of motor 5-3 will carry an increased load and will reduceits speed of rotation. This reduces the counter emf and raises thecurrent flowing through the winding R5L a suflicient amount to actuatethe armature associated with the relay windings and to open switch 1R5and to close switch 2R5. The opening of switch 1R5 interrupts thecircuit through the motor 59 by way of the low resistance winding REL.This permits a holding current of a small amount to flow through theauxiliary high resistance winding RSI-I in a manner analogous to theaction of the holding of relay contact 1R4 in open position by currentflowing through the holding high resistance winding PAH. It will be seenthat at this point in the cycle of operations current is flowing throughthe holding winding R3 maintaining contacts 1R3 and 2R3 closed, currentis flowing through holding winding R4H holding relay contact 1R4 openand relay contact 2R4 closed, and current is flowing through holdingwinding RSI-I maintaining contact 1R5 open and contact 2R5 closed.

The closing of relay contact 2R5 will complete the circuit through motor60, which is provided with a field winding 61, by way of the lowimpedance relay winding R6L. The motor 60 actuates the third window andraises it. When this window reaches the limit of its travel, theincreased load upon the motor 6% reduces the counter emf and increasesthe armature current. This increase in armature current is suthcient toproduce an increase of magnetic flux in Winding R6L to operate thearmature of the relay. The actuation of the armature opens normallyclosed relay contact 1R6 and closes normally open relay contact 2R6. Theopening of switch 1R6 permits an energization of the high impedancewinding RdH which will maintain the relay R6 in its actuated position,that is, with switch 1R6 open and switch 2R6 closed in a manneranalogous to the action of holding windings RdI-I and R5H.

The closing of switch 2R6 will energize the motor 7%, which is providedwith a shunt field winding 71. Motor '70 will raise the fourth window ofthe automotive vehicle. When this window reaches its raised position,the increased load upon the motor 7% will cause the relay winding R7L toactuate the relay armature to open normally closed switch 1R7 and toclose normally open switch 2R7. The opening of the normally closed relayswitch 1R7 will permit the energization of the high resistance holdingwinding R7H.

The closing of switch 2R7 will energize the motor 80, which is providedwith a field winding iii. The motor 30 will drive the mechanism whicherects the top of the convertible car. When the automotive top reachesits erected position, it will mechanically open limit switch LS. Whenthis occurs, the circuit through holding winding R3 is broken andswitches 1R3 and 2R3 will return to their normally open positions. Theopening of switch 2R3 will interrupt the current through the holdingwinding RdH. When this occurs, switch 2R4 will move to its openposition, thus interrupting the current through holding winding RSI-I.When this occurs, switch 2R5 will open, interrupting the current throughholding winding RfiI-i, thus permitting the switch 2R6 to resume itsnormally open position. This causes an interruption of current flowthrough the holding winding RiH and permits the switch 2R7 to openstopping the top motor 30. When the top 7 is up, the water sensitiveswitch W can no longer energize the relay winding R2 because the limitswitch LS now interrupts the circuit.

The cycle of operations initiated by the water sensitive switch can bestopped at any time by opening the normally closed manual switch 18.When the manual switch 18 is open or the ignition switch K is closed,the water sensitive control circuit is rendered inoperative and theWindows and top may be controlled by the normal controls with which theautomotive vehicle may be fitted.

It will be understood, of course, that the sequential operation of themotors 4t), 5t), 6t 7t? and 80 are employed in an automotive vehicleowing to the lack of capacity of the normal storage battery of a car.

It will be seen that I have accomplished the objects of my invention. Ihave provided a water responsive control circuit enabling the windows ofan automotive vehicle to be raised in succession followed by theerection of the collapsible top in response to water from raindrops orsnow acting upon a water sensitive sw' ch. The window raising motor isadapted to be de-energized upon the interposition in an increased loadfrom any cause. Thus, if a child were in the vehicle and thrust an armor its head in the path of the window travel, the window raising motorwould be de-energized before the child could be injured. The cycling ofthe control circuit is completed upon the raising of the top and theentire circuit automatically de-energized.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is Within the scope of myclaims. It is further obvious that various changes may be made indetails within the scope of my claims without departing from the spiritof my invention. It is therefore to be understood that my invention isnot to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In a water responsive control circuit of the character described afirst relay winding, a first normally open first relay switch, a secondnormally open first relay switch, water sensitive means for energizingthe first relay winding, circuit means completed by the closing of thefirst normally open first relay switch for holding the first relaywinding in energized condition, a motor, a low impedance second relayWinding, a normally closed second relay switch, circuit means includingsaid second normally open first relay switch and said normally closedsecond relay switch and said low impedance second relay windingconnected in series for energizing said motor, an auxiliary highimpedance winding shunted across said low impedance second relay windingand said normally closed second relay switch, the construction beingsuch that the energization of said low impedance second relay windingwill open said normally closed second relay switch and permit theenergization of said high impedance second relay winding to hold thenormally closed second relay switch in open position thereby maintainingthe motor in de-energized condition.

2. In a water responsive control circuit of the character described afirst relay winding, a first normally open first relay switch, a secondnormally open first relay switch, water sensitive means for energizingthe first relay winding, circuit means completed by the closing of thefirst normally open first relay switch for holding the first relaywinding in energized condition, a first motor, a low impedance secondrelay winding, a normally closed second relay switch, a normally opensecond relay switch, circuit means including said second normally openfirst relay switch and said normally closed second relay switch and saidlow impedance second relay winding connected in series for energizingsaid first motor, an auxiliary high impedance second relay windingshunted across said low impedance second relay winding and said normallyclosed second relay switch, a second motor, a circuit for energizingsaid second motor including said normally open second relay switch, theconstruction being such that the energization of said low impedancesecond relay winding will open said normally closed second relay switchand close said normally open second relay switch whereby to de-energizesaid first motor and initiate the circuit through said second motor.

3. A water responsive control circuit as in claim 2 including meansresponsive to a predetermined movement of said second motor forinterrupting the circuit through said first relay winding.

4. A water responsive control circuit as in claim 2 including a keycontrolled relay winding, a normally closed key controlled relay switchand circuit means for connecting said normally closed key controlledswitch in series with said first relay winding whereby to prevent theenergization of said first relay winding whenever said key controlledrelay winding is energized.

5. In a water responsive control circuit of the character described afirst relay winding, a first normally open first relay switch, a secondnormally open first relay switch, water sensitive means for energizingthe first relay winding, circuit means completed by the closing of thefirst normally open first relay switch for holding the first relaywinding in energized condition, a first motor, a low impedance secondrelay winding, a normally closed second relay switch, a normally opensecond relay switch, circuit means including said second normally openfirst relay switch and said normally closed second relay switch and saidlow impedance second relay winding connected in series for energizingsaid first motor, an auxiliary high impedance second relay windingshunted across said low impedance second relay winding and said normallyclosed second relay switch, a second motor, a low impedance third relaywinding, a normally closed third relay switch, a normally open thirdrelay switch, circuit means including said normally open second relayswitch, said normally closed third relay switch and said low impedancethird relay winding connected in series for energizing said secondmotor, an auxiliary high impedance third relay winding shunted acrosssaid low impedance third relay winding and said normally closed thirdrelay switch, a third motor, a circuit for energizing said third motorincluding said normally open third relay switch, the construction beingsuch that the energization of said low impedance third relay windingwill open said normally closed third relay switch and close saidnormally open third relay switch whereby to de-energize said secondmotor and initiate the circuit through said third motor.

6. A water responsive control circuit as in claim 5 including meansresponsive to a predetermined movement of said third motor forinterrupting the circuit through said first relay winding whereby tointerrupt the circuit through said holding high impedance second relaywinding and thus interrupt the circuit through said holding highimpedance third relay winding to permit the normally open third relayswitch to resume its open position and interrupt the circuit throughsaid third motor.

7. In a water responsive control circuit of the character described amotor, a low impedance relay winding, a normally closed relay operatedswitch and a normally open switch, a circuit for energizing said motorincluding said low impedance relay winding, said normally closed relayswitch and said normally open switch connected in series, an auxiliaryhigh impedance winding shunted across said low impedance relay windingand said normally closed relay switch, the construction being such thatupon the energization of said motor by the closing of said normally openswitch the motor will be energized and upon the energization of said lowimpedance winding owing to an increase in armature current through themotor said motor circuit will be interrupted by the opening of saidnormally closed relay operated switch maintained in such openedcondition by current flowing through the shunted high impedance relaywinding.

References Cited in the file of this patent UNITED STATES PATENTS

